Accuracy of Multiple Pulse Oximeters in Stable Critically Ill Patients

Marie-Anne Blanchet; Gabriel Mercier; Antoine Delobel; Emi Nayet; Pierre-Alexandre Bouchard; Serge Simard; Erwan L'Her; Richard D Branson; François Lellouche

doi:10.4187/respcare.10582

Accuracy of Multiple Pulse Oximeters in Stable Critically Ill Patients

Respir Care. 2023 May;68(5):565-574. doi: 10.4187/respcare.10582. Epub 2023 Jan 3.

Authors

Marie-Anne Blanchet¹, Gabriel Mercier¹, Antoine Delobel¹, Emi Nayet¹, Pierre-Alexandre Bouchard¹, Serge Simard¹, Erwan L'Her², Richard D Branson³, François Lellouche⁴

Affiliations

¹ Department of Medicine, Centre de recherche, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Canada.
² Medical Intensive Care Unit, CHRU Brest, La Cavale Blanche, Brest, France.
³ Department of Surgery, Division of Trauma and Critical Care, University Cincinnati, Cincinnati, Ohio.
⁴ Department of Medicine, Centre de recherche, Institut Universitaire de Cardiologie et de Pneumologie de Québec, Université Laval, Québec, Canada. francois.lellouche@criucpq.ulaval.ca.

Abstract

Background: An accurate S_pO₂ value is critical in order to optimally titrate oxygen delivery to patients and to follow oxygenation guidelines. Limited prospective data exist on real-world performance of pulse oximeters in critically ill patients. The objective of this study was to assess accuracy and bias of the S_pO₂ values measured by several oximeters in hospitalized subjects.

Methods: We included stable adults in the ICU with an arterial catheter in place. Main exclusion criteria were poor S_pO₂ signal and S_pO₂ > 96%. In each subject, we simultaneously evaluated 4 oximeters: Nonin (Plymouth, Minnesota) embedded in the FreeO₂ device (OxyNov, Québec City, Québec, Canada), Masimo (Radical-7, Masimo, Irvine, California), Philips (FAST, Philips, Amsterdam, the Netherlands), and Nellcor (N-600, Medtronic, Minneapolis, Minnesota). Arterial blood gases were drawn and simultaneously each oximeters' S_pO₂ values were collected. S_pO₂ values were compared to the reference (arterial oxygen saturation [S_aO₂ ] value) to determine bias and accuracy. The ability for oximeters to detect hypoxemia and the impact of oximeters on oxygen titration were evaluated.

Results: We included 193 subjects (153 male, mean age 66 y) in whom 211 sets of measurements were performed. The skin pigmentation evaluated by Fitzpatrick scale showed 96.2% of subjects were light skin (types 1 and 2). One oximeter overestimated S_aO₂ (Philips, +0.9%), whereas the 3 others underestimated S_aO₂ (Nonin -3.1%, Nellcor -0.3%, Masimo -0.2%). S_aO₂ was underestimated with Nonin oximeter in 91.3% of the cases, whereas it was overestimated in 55.2% of the cases with Philips oximeter. Moderate hypoxemia (S_aO₂ 86-90% or P_aO₂ 55-60 mm Hg) was detected in 92, 33, 42, and 11% of the cases with Nonin, Nellcor, Masimo, and Philips, respectively.

Conclusions: We found significant bias and moderate accuracy between the tested oximeters and the arterial blood gases in the studied population. These discrepancies may have important clinical impact on the detection of hypoxemia and management of oxygen therapy.

Keywords: hyperoxemia; hypoxemia; oximeter; oxygen therapy monitoring; pulse oximetry.

MeSH terms

Adult
Aged
Critical Illness* / therapy
Humans
Hypoxia / diagnosis
Male
Oximetry
Oxygen
Prospective Studies
Respiration Disorders*

Substances

Oxygen